There are a lot of good cops out there, you just have to approach the situation and understand it from the cop's perspective.
A traffic stop is THE MOST dangerous situation for a peace officer. More cops killed on traffic stops than anything else in their profession.
Here are a few tips that will help put the approaching officer at ease and very likely impact his decision making while standing by your rear corner panel.
1. Pull over immediately to the side of the road. If he does not like where you stopped, he will get on his PA or signal for you to move to an area he feels is safer.
2. Turn the wheels full lock to the right if on the right side of the road. To the left for the left side of the road.
3. Turn the car off, put the keys on the dash, leave it in gear, set the emergency brake, turn off the radio.
4. Roll down the windows and turn the interior lights on.
5. Put your hands on the steering wheel at the 11 and 1 positions crossed over at the wrist.
6. When he approaches the car and asks you for documentation, explain where it is and ask him if you may retrieve it telling him which hand to retrieve it.
7. One you dig out the documents put your hands back on the steering wheel at 11 and 1.
8. Preferably don't be a dick and answer "yes sir" and "no sir."
If you follow these steps, what you have likely done is just put a fellow human being at ease while he is doing something more dangerous than most of us will do in our lifetimes or at least with any regularity. And a person not worrying about being shot or run over is usually a lot easier to deal with when it comes to leniency.